隨著現代人環保意識提高和提倡節能減碳，傳統的白熾燈因使用壽命短、發光效率低、汰換率高，不符合環保提倡之訴求，且近年來地球也面臨暖化嚴重、能源枯竭等現實性問題，因此若要改善諸如此類的問題，將必須從日常生活照明工具下手。近年來利用發光二極體 (Light Emitting Diode- LED)，來當作替換白熾燈、鹵素燈已成為時代的潮流。因LED具有壽命長、體積小、亮暗反應速度快、環保無使用汞和水銀材料，發光效率高，但由於LED的亮度取決於順向導通電流，因此供應一恆定電流為LED驅動電路首要的課題。
本研究電路綜合以下三點缺點做電路之改善。第一點在本研究中使用MOSFET來取代BJT來產生負溫度係數，大大的減少佈局面積和消耗功率，第二點本研究在電流控制震盪器端使用溫度補償電路來改善PWM，使其輸出能夠抗溫度飄移，最後本設計電壓輸出端使用一AND邏輯閘將PWM調光端和過熱保護電路端 (OTP) 結合做數位控制，其優點是每個通道的電流並不會受輸出電壓的影響，且利用AND閘將保護裝置和PWM調光做同步輸出，可增加其切換的速度，提高保護效用的精確度。
本研究之LED驅動IC，電源電壓為3.3V，輸出電流在溫度-25℃至100℃之間時，其輸出電流值隨溫度偏移率不超過1%，PWM調光控制端，其工作頻率隨溫度變化可達100KHz±15%，而可調之工作週期範圍可從最低10%到90%，用來作為調節白光LED亮度，使用CIC所提供之TSMC 0.35μm 2P4M 3.3/5V CMOS 製程，晶片面積為1.1×1.0 mm2。

In recent years, the traditional incandescent has life is short, low luminous efficiency, high replacement rate, does not meet the demands of environmental advocate, so being replaced by light emitting diode. Because LED has a long life, small size, light, fast response, environmental protection without the use of mercury and mercury materials, high luminous efficiency, but LED brightness depending on the forward current, therefore, how to supply constant current is becoming the most important topic of LED driving circuit.
In this paper, the following three points to improve integrated circuit. The first, replace BJT with MOSFET to produce voltage of negative temperature coefficient for reducing layout area and power consumption. The second, this design circuit, the current controlled oscillator with temperature compensation to improve the PWM dimming. The final, the AND gate is combined with overheat protection circuit (OTP) signal and PWM signal. The advantage is that the output voltage does not affect the each channel current, increase switch speed and improve the accuracy of the protective effect. The duty cycle of PWM be controlled to by external dc bias 0.6V to 2.3V. Post-layout simulation shows that Vout channel provides dimming frequency about 100KHz changes from -25℃ to 100℃ and the duty cycle of PWM which adjustable from 10% to 90%. In addition, the current channel provides 30mA between -25℃ to 100℃, when power supply Vdd is 3.3V. Besides, It is fabricated with CIC provided by TSMC 0.35μm 2P4M 3.3V/5V CMOS process in an active area of 1.1 mm × 1.0 mm.

目錄
論文審定書 i
誌謝 ii
摘要 iii
Abstract iv
目錄 v
圖目錄 viii
表目錄 xii
第一章 緒論 1
1.1 研究背景 1
1.2 LED驅動IC發展 2
1.3 研究動機 22
1.4 論文大綱 23
第二章 LED之發光原理與整體架構簡介 24
2.1 LED發光原理 24
2.2 LED元件特性 26
2.2.1 LED內部量子效率 (Internal quantum efficiency) 26
2.2.2 LED外部量子效率 (External quantum efficiency) 26
2.3 LED之陣列結構 27
2.3.1 LED串聯陣列 27
2.3.2 LED並聯陣列 28
2.3.3 LED混聯陣列 29
2.3.4 LED交叉陣列 29
2.4 PWM原理 30
2.4.1 直接啟用式調光 30
2.4.2 串列調光 30
2.4.3 並聯調光 30
2.5 白光LED驅動電路分析 31
2.5.1 白光LED驅動電路之基本需求 31
2.5.2 白光LED驅動電路之分類及簡介 31
2.5.3 各種白光LED驅動電路特性介紹和比較 37
2.6 LED驅動IC架構理論 41
2.6.1 本研究之電路架構簡介 41
第三章 電路設計架構 43
3.1 溫度補償電路 (Temperature Compensation Circuit) 43
3.2 電壓轉換電流調節電路 (V to I converters) 47
3.3 電流控制環形震盪器 (CCO) 48
3.4 PWM 調光控制之比較器 51
3.5 Overheat Protection Circuit (OTP) 52
第四章 模擬結果與討論 54
4.1 溫度補償電路 (TPC) 54
4.2 電壓轉換電流調節電路 56
4.3 電流控制環形震盪器 (CCO) 58
4.4 脈波寬度調變電路 (PWM) 62
4.5 過熱保護電路 (OTP) 69
4.6 本研究之整體電路輸出 (Vout) 71
4.7 本研究之設計電路和相關參考文獻比較 75
第五章 結果討論與未來展望 76
5.1 結果討論 76
5.2 未來展望 77
參考文獻 78
Published 84

參考文獻
[1] 聚積科技取自網頁資料：http://www.mblock.com.tw/tw
[2] 點晶科技取自網頁資料：http://www.siti.com.tw/info/info1.html
[3] 晶綺科技取自網頁資料：http://www.starchips.com.tw/
[4] Y. Wang, M. Gao, and D. Guo, “Design of 16-bits constant-current LED driver,” International Conference on IEEE, Anti-Counterfeiting Security and Identification in Communication, pp. 53-56, Jul. 2010.
[5] J. Lu, and X. Wu, “A PWM Controller IC for LED driver used to multiple DC-DC topologies,” Asia-Pacific Power and Energy Engineering Conference, pp. 1-4, Mar. 2009.
[6] X. Zou, K. Yu, Z. Zheng, X. Chen, Z. Zou, and D. Liao, “Dynamic current limitation circuit for white LED driver,” IEEE Asia Pacific Conference on Circuits and Systems, pp. 898-901, Dec. 2008.
[7] J. Qiu, and L. He, “A LED driver IC with constant current and temperature compensation,” IEEE International Conference on Computer Science and Information Technology, pp. 162-164, Jul. 2010.
[8] J. T. Hwang, K. Cho, D. Kim, M. Jung, G. Cho, and S. Yang, “A simple LED lamp driver IC with intelligent power-factor correction,” International on Solid-State Circuits Conference Digest of Technical Papers, pp. 236-238, Feb. 2011.
[9] Z. Y. Huang, J. S. Chiang, W. B. Yang and C. H. Wang, “A new temperature independent current controlled oscillator,” International Symposium on IEEE, Intelligent Signal Processing and Communications Systems, pp. 1-4, Dec. 2011.
[10] 楊賜麟譯，2010，半導體物理與元件，初版，台中，滄海書局。
[11] 周志敏、周紀海、紀愛華，2008，LED驅動電路設計與應用，初版，台北，五南圖書。
[12] M. Z. Dai, and I. C. Deng, “High efficiency boost driver for white LED,” M.S. thesis, Taipei Chengshih University of Science and Technology in partial Fulfullment of the Requirements for the Degree of Master in Institute of Electronic Engineering, Taipei, Taiwan, Jul. 2012.
[13] S. Cha, D. Park, Y. Lee, C. Lee, J. Choi, J. Lee, and H. Lee, “AC/DC converter LED driver for lightings,” IEEE International Conference on Consumer Electronics, pp. 706-708, Jan. 2012.
[14] S. S. Prasad, and P. Mandal, “A CMOS beta multiplier voltage reference with improved temperature performance and silicon tenability,” 17th International Conference on IEEE, VLSI Design, pp. 551-556, 2004.
[15] M. K. Adimulam, and K. K. Movva, “A low power CMOS current mode bandgap reference circuit with low temperature coefficient of output voltage,” Asia Pacific Conference on Postgraduate Research in Microelectronics and Electronics, pp. 144-149, Dec. 2012.
[16] N. Laflamme Mayer, O. Valorge, Y. Blaquiere, and M. Sawan, “A low-power, small-area voltage reference array for a wafer-scale prototyping platform,” 8th IEEE International, NEWCAS Conference, pp. 189-192, Jun. 2010.
[17] R. Dehghani, and S. M. Atarodi, “A new low voltage precision CMOS current reference with no external components,” IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, vol. 50, no. 12, pp. 928-932, Dec. 2003.
[18] G. Kapur, C. M. Markan, and V. P. Pyara, “On-chip tunable wide ranged multiple output voltage reference,” Proceedings of IEEE, Southeaston, pp. 1-4, Mar. 2012.
[19] T. C. Lu, H. W. Zan, and M. D. Ker, “Temperature coefficient of poly-Silicon TFT and its application on voltage reference circuit with temperature compensation in LTPS process,” IEEE Transaction on Electron Devices, vol. 55, no. 10, pp. 2583-2589, Oct. 2008.
[20] S. Liu, and R. J. Baker, ”Process and temperature performance of a CMOS beta-multiplier voltage reference,” Midwest Symposium on IEEE, Circuits and Systems, pp. 33-36, Aug. 1998.
[21] B. Razavi, “Design of analog CMOS integrated circuits,” Boston: McGraw-Hill, 2000.
[22] Y. Y. Chen, S. A. Zhong, and H. Dang, “Design of Bandgap Current Reference with Wide Range of Output Voltage in a 0.18μm Bi-CMOS Process,” WRI World Congress on IEEE, Computer Science and Information Engineeringg, pp. 384-386, Apr. 2009.
[23] C. Azcona, B. Calvo, S. Celma, N. Medrano, and P. A. Martinez, “Low-voltage low-power CMOS rail-to-rail voltage-to-current converters,” IEEE Transactions on Circuits and Systems Circuits and Systems I: Regular Papers, vol. 60, no. 9, pp. 2333-2342, Sep. 2013.
[24] W. Surakampontorn, V. Riewruja, K. Kumwachara, C. Surawatpunya, and K. Anuntahirunrat, “Temperature-insensitive voltage-to-current converter and its applications,” IEEE Transactions on Instrumentation and Measurement, vol. 48, no. 6, pp. 1270-1277, Dec. 1999.
[25] Q. A. Khan, S.K. Wadhwa, and K. Misri, “A low voltage switched-capacitor current reference circuit with low dependence on process, voltage and temperature,” 16th International Conference on IEEE, VLSI Design Proceedings, pp. 504-506, Jan. 2003.
[26] B. Fotouhi, “All-MOS voltage-to-current converter,” IEEE Journal of solid-state circuits, vol. 36, no. 1, Jan. 2001.
[27] D. S. Masmoudi, and A. Fakhfakh, “A new low voltage CMOS current controlled oscillator with minimum phase noise,” The 16th International Conference on Microelectronics, ICM 2004 Proceedings, pp. 616-619, Dec. 2004.
[28] M. S. Jahan, and J. H. Holleman, “An ultra-low-power 400MHz VCO for MICS band application,” International Conference on Electrical and Computer Engineering, pp. 318-321, Dec. 2010.
[29] S. Pookaiyaudom, A. Thanachayanont, and R. sitdhikorn, “Current amplitude control circuits suitable for current-mode oscillators,” Electronics Letters, vol. 33, no. 1, pp. 2-3, Jan. 1997.
[30] Y. S. Shyu, and J. C. Wu, “A process and temperature compensated ring oscillator,” The First IEEE Asia Pacific Conference on ASICs, pp. 283-286, 1999.
[31] Y. Sun, Y. S. Wang, and F. C. Lai, “Low power high speed switched current comparator,” The 14th International Conference on Mixed Design of Integrated Circuits and Systems, pp. 305-308, Jun. 2007.
[32] J. F. Wang, and J. H. Duan, “Design of an ultra high-speed voltage comparator,” Second Pacific-Asia Conference on IEEE, Circuit, Communications and System, pp. 145-148, Aug. 2010.
[33] Y. Sun, Y. Ye, and F. Lai, “Power efficient high speed switched current comparator,” 7th International Conference on IEEE, ASIC, ASICON '07., pp. 581-584, Oct. 2007.
[34] P. E. Allen, and D. R. Holberg, “CMOS analog circuit design,” New York: Oxford University Press, 2002.
[35] Y. T. Hsieh, B. D. Liu, J.-F. Wu, C. L. Fang, H. H. Tsai, and Y. Z. Juang, “A high-dimming-ratio LED driver for LCD backlights,” IEEE Transactions on Power Electronics, vol. 27, no. 11, pp. 4562-4570, Nov. 2012.
[36] Y. Yang, Z. Song, and Y. Gao, “Design of high-Power white LED drive chip with fully integrated PWM dimming function,” Symposium on Photonics and Optoelectronic, pp. 1-4, Jun. 2010.
[37] J. Garcia, A. J. Calleja, E. López rominas, D. Gacio Vaquero, and L. Campa, “Interleaved buck converter for fast PWM dimming of high-brightness LEDs,” IEEE Transactions on Power Electronics, vol. 26, no. 9, pp. 2627-2636, Sep. 2011.
[38] C. Y. Ho, T. W. Chou, and C. H. Lin, “System parameters comparison between four-phase and six-phase PWM dimming control for backlight inverter,” The 5the IEEE Conference on Industrial Electronics and Applications, pp. 1130-1135, Jun. 2010.
[39] Y. J. Chen, and Y. H. Zhang, “Design of voltage-mode/current-mode PWM-based two/three-stage multiphase voltage doublers for white LED driver,” M.S. thesis, Department of Computer Science & Information Engineering, Chaoyang University of Technology, Taichung, Taiwan, 2008.
[40] D. S. Wang, P. S. Zheng, and H. Y. Wang, “Pulse width modulation controlled buck converter for LED driver,” M.S. thesis, Degree of Master of Engineering in Electronic Engineering, National Kaohsiung University of Applied Sciences in Partial Fulfillment of the Requirements, Kaohsiung, Taiwan, Jul. 2011.
[41] Y. C. Huang, and F. Z. Lin, “Analysis and implemention fo LED driver with active power factor correction,” M.S. thesis, Department of Electrical Engineering, National Central University, Taoyuan, Taiwan, Jun. 2013.
[42] C. Z. Wu, and Q. W. Wang, “A study of LED driver with optimal PWM control system,” M.S. thesis, Graduate Institute of Opto-Mechatronics, National Chung Cheng University, Chiayi, Taiwan, Jun. 2010.
[43] M. G. V. Bautista, W. R. Liou, and M. L. Yeh, “Dimmable multi-channel RGB LED driver,” IEEE International Energy Conversion Congress and Exhibition, pp.1259-1262, Jun. 2013.
[44] W. C. Yang, and Dr. C. S. Moo, “Efficient driver for dimmable white LED lighting,” M.S. thesis, Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan, Jun. 2011.
[45] Y. J. Huang, X. R. Xie, and X. Z. Jiang, “Design and implementation of non E-cap high power factor LED driver,” M.S. thesis, Department of Electrical Engineering, Electrical Engineering National Dong Hwa University, Hualien, Taiwan, 2011.
[46] J. Y. Lee, T. J. Liang, and J. H. Huang, “Implementation of driving circuit for high brightness LEDs,” M.S. thesis, Department of Electrical Engineering., College of Electrical Engineering and Computer Science National Cheng Kung University, Tainan, Taiwan, Jul. 2009.
[47] P. Alex, C. Paulo, and P. Tales, “A low power thermal protection topology,” The 24th International Conference on Microelectronics, pp. 1-4, Dec. 2012.
[48] M. Szermer, M. Janicki, P. Pietrzak, Z. Kulesza, and A. Napieralski, “PTAT sensor for chip overheat protection,” The 26th annual IEEE on Semiconductor Thermal Measurement and Management Symposium, pp. 176-179, Feb. 2010.
[49] Y. Han, J. Chen, and J. Liang, “Summary of HV power ICs protecting circuit design,” The 6th International Conference on Solid-State and Integrated-Circuit Technology, pp. 135-138, 2001.